Fortress Europe- European Fortifications Of World War II

by J E Kaufmann

  Large anti-tank bunkers protected key crossing points in the Peel Line, as on the frontier lines. The Dutch used great ingenuity in camouflaging their bunkers as houses, hay stacks, and a variety of other things. The Peel Line covered almost three times the distance of the Grebbe Line, but comprised only about 290 machine gun bunkers, 245 of which were of the light three embrasure type. There were also 79 special armored turrets but only 13 anti-tank gun bunkers. The water barriers and the swampy terrain of the Peel Marshes formed the main barriers, but on either end of the line the terrain could not be flooded. The gaps on the northern and southern end of the line left it vulnerable, especially since there were no additional army units to defend them. Between Weert and the Belgian defenses on the Albert Canal a 45 km gap was left open.

  The F and Q Lines, built along the main water courses in the north, were only intended for delaying actions. The Q Line, which followed several canals, ran from southeast of Delfzij on the mouth of the Ems to Veendam and Emmen. The F Line began a little further south of Emmen: and followed the Hoogeveensche Canal to Meppel and the Zuider Zee. Fortifications were few in this region.

  WEAPONS AND EQUIPMENT

  Coastal Defense Ships Guns: 240-mm 150-mm Coast Defense Guns:* 280-mm (Krupp) 150-mm OF (Krupp) 120-mm 75-mm 105-mm Flak (Bofors) 75-mm Flak (Vickers) Army Weapons: 75-mm (3 types) 80-mm Model 1880 105-mm 120-mm Model 1880 120-mm U14 150-mm Infantry Weapons: 50-mm AT Gun (Bofors) 47-mm AT Gun (Rheinmetall) 37-mm AT Gun (Rheinmetall) 81-mm Stokes Mortar Heavy MG, 7.9-mm Light MG, 6.5-mm (Madsen) Range in meters unknown unknown 12,800 14,300 unknown 7,500 unknown 10,000 (vertical) 8,200, 8,450 & 10,600 3,500 16,500 7,600 7,250 8,650 800 600 600 2,100 1,700 1,000

  WORLD WAR II

  American attache LTC Brown's prediction came true, probably even faster than he believed possible. The Dutch only resisted for four days in May 1940. Although the German invasion of the Netherlands was a secondary operation compared to the invasion of Belgium, it was carried out with astounding efficiency. Early in the morning of May 10 the German 7th Air Division and 22nd Air Landing Division began their descent over Holland by parachute and in aircraft. The leading assault force had successfully surprised the defenders of the key bridges over the rivers of the Southern Front leading into Fortress Holland. Meanwhile, on the frontier, special German troops, the Brandenbergers, disguised in Dutch uniforms and followed by armored trains, attempted to capture some of the key bridges near the border so an armored force could race through to relieve the paratroopers. They succeeded in taking only one bridge, but it proved to be enough.

  At the time of the attack as many as twenty-five Dutch frontier battalions manned the frontier defenses, nine of which were stationed on the Maas Line, three on the Ijssel Line, five on the open eastern border area, between the Ijssel and F Lines, six in the Maastricht Appendage of the province of Limburg, five in Friesland, four in Zeeland, three on the South Front of Fortress Holland, two at Fort Den Helder, one at fort Den Oever, and one at fort Kornwerderzand. Of the ten army divisions most were located in the vicinity of Fortress Holland and four manned the Peel Line.

  General Henri G. Winkelman, commander-in-chief of Dutch forces, and his superiors had made the decision that if a German invasion came they would withdraw the army into Fortress Holland and abandon the defenses of the Brabant. The heavy concentration of Dutch forces in Fortress Holland after a fighting withdrawal should have made it possible to successfully resist German assaults. Unfortunately, the events of the war did not unfold as predicted. In the first place, the weather did not cooperate that winter and spring and it did not rain enough to make the water obstacles efficient. In the second place, the Germans did not behave as predicted. They attacked swiftly and suddenly, leaving their opponents with too little time to activate their water defenses.

  Elements of the German 7th Airborne and 22nd Air Landing divisions launched the initial paratrooper assault on the bridges of Moerdijk, Dordrecht, and Rotterdam to breach the Holland Deep, the Waal, and the Lek River, in an attempt to open a back door into Fortress Holland for air-landed elements who were to land near The Hague and capture the government and military high command. However, the Germans failed to take the bridge at Dordrecht so that only the south side of the Rotterdam crossings fell on the first day. The landings inside Fortress Holland were not as successful, but with the bridge at Moerdijk solidly in German hands, the river barriers were effectively breached.

  The German endeavor to force crossings of the Maas and Ijssel, and to penetrate the Grebbe Line failed when several armored trains were destroyed by the Dutch. At Gennep, on the other hand, the Brandenbergers' trick succeeded so that an armored train passed over the Maas and was shortly followed by the 9th Panzer Division which began its race across the North Brabant to relieve the paratroopers.

  In the North, the German 1st Cavalry Division quickly crossed the Q Line, reaching the Wons Position by May 11. Here it came face to face with the 650 men of the Dutch 33rd Infantry Regiment, who were later joined by additional troops. The fighting raged around Rotterdam and Dordrecht from May 11 to May 12. The first elements of the 9th Panzer Division passed over the Moerdijk on May 12, crossing the river in the afternoon. The Maas and Peel Lines had been penetrated and generally abandoned after the first day. On May 12, the Wons Position collapsed and the Germans were at the approaches to the Great Dike. By that time, other German forces had already penetrated the Ijssel Line and were attacking the Grebbe Line, which was breached by a German SS regiment. On May 13, two German divisions continued the advance, breaking through the line and forcing the Dutch to fall back on the New Water Line. Their swift success was due to the fact that most of the Dutch reserves had been tied up in fighting the German air landed troops.

  When Fort Kornwerderzand was attacked, Fortress Holland stood on the verge of collapse. Despite the odds, the fort's garrison of 225 men soundly repelled the German assault with the help of the 150-mm guns of a gunboat from Den Helder. The fort did not surrender until it was ordered to do so by the Dutch commanderin-chief on May 14, when the rest of the army also laid down its arms.

  Only the Dutch battalions in Zeeland held out until May 18 when the last French divisions withdrew, having arrived too late to help the Dutch. The German SS Verfugungs Division, a regiment-size unit, attacked the Bath Position on May 14 and the Zandijk Position the next day. When the Dutch forces surrendered, their last defense line had already fallen.

  Most of the invading German troops involved in this operation were not first rate, and the Dutch might have held out longer had it not been for the air assault.

  The Germans put some of the Dutch defensive positions,including coastal positions like Hoek van Holland, back into operation after the surrender of the Netherlands. In 1940 they also restored the fortress and added casemates at Willemstad, built a couple of casemates on to the forts of the Great Dike and converted other positions for their own use throughout the country.

  Den Oever, Block IX. One of the fort's larger blocks which mounted MG. Near the cloche a seam can be seen where this position was built in two parts. In the rear (left side of photo) an open position for a MG and behind it two doors which were the latrines (Dutch kept them outside the blocks). (Kaufmann)

  Ft. Pannerdern. Above the old walls in the fort's moat can be seen an armored artillery casemate for two guns. (Kaufmann)

  Dutch MG turret mounted in concrete position. There was usually enough space for 2 to 3 men. (Kaufmann)

  Dutch "Pyramid." These shelters were usually found in lines and used as shelters and CPs. The entance was covered by a firing position, but there were no external weapons embrasures. (Kaufmann)

  Heavy MG behind armored plate in light bunker.

  Dutch Three Embrasure BunkerType SZW 100.

  Chapter 5

  SWITZERLAND

  BACKGROUND

  The Swiss military forces engaged in their last major conflict during the Napoleonic Era and saw their last combat action in 1846, during a minor civil
war that inflicted few casualties. Beginning in the thirteenth century, the country's rugged terrain had made it possible for Switzerland to defy the authority of the Holy Roman Empire until its cantons formally achieved their independence in 1648. The Congress of Vienna in 1815 formally recognized Switzerland's neutrality, which it has preserved ever since. Nevertheless, in 1856, 1870, 1914, and 1939 the Swiss army, mostly a militia force, mobilized to prevent external conflicts from spilling over their borders.

  In the past, fortifications had not been the key to Switzerland's success, as much as the character of its tough mountain people. However, after 1870 the situation changed because the traditional methods of defense were no longer enough against the new massive conscript armies equipped with long-range weapons.

  The socio-economic and political. heart of Switzerland occupied the western third of its territory, on the Mittelland Plateau, shielded on one side by the Jura Mountains and on the other by the Alps. It was through this very area that the main invasion route passed, leading from the Bodensee to Geneva. The northern sector of this heartland, extending along the Rhine, starting at Basel, was not as easily defended and did not present a formidable barrier against modern weapons. This does not mean that this terrain was indefensible, but rather no longer impassable.

  Since Switzerland had become industrialized, the likelihood of its armed forces abandoning its new and growing cities to pull back into the mountain fastness and resist in the old manner diminished. Thus fortifications grew in importance since they made it possible to close off key valleys and form solid lines of defense.

  The Swiss fortifications in the western region ranged in age from the Middle Ages to the Renaissance. More defensive works were added in the nineteenth century, but, with the advent of the torpedo shell in the 1880s, they soon became totally obsolete. Thus special commissions were appointed in 1880 and 1882 to study the problem. The work of these commissions resulted in the creation of two defensive zones: one for the populated areas of the west and the other for the Alpine region. This remained the basis of the Swiss defensive scheme through the first part of the twentieth century. To design the new fortifications, Swiss officers were sent to investigate German, Austrian, and Belgian techniques. What emerged from these investigations was an eclectic style that combined elements of the various schools of fortification. Even the equipment reflected this eclectic style. For instance, the Swiss combined German guns with French carriages, and adopted the German Gruson gun turret.

  First priority went to defending the St. Gotthard area where a new railroad tunnel had been completed in 1882. Work on a series of forts and defenses for the St. Gotthard Pass began in 1887. The year of 1890 saw the completion of Forts Airolo and Galenhi.itten that included characteristics of the Belgian Brialmont forts. Forts Briihl and Bauzberg were built shortly after that on the other side of the valley. They included armored gun turrets cut into the rock.

  The defense of the region southeast of Lake Leman or Geneva had second priority. Here "mobile" 53-mm gun turrets were used to economize on some of the positions. Fort Savatan on the lower plateau and Fort Dailly on the higher plateau formed Fortress St.Maurice in 1894. Curiously, Fortress St. Gotthard and Fortress St. Maurice appear to have defended areas that should not have been considered too vulnerable at a time when a conflict was looming between Germany and France. These fortresses were two of the cornerstones of the National Redoubt created by the commission of 1882. Work and improvements continued on all the fortifications during the Great War.

  MAJOR FORTIFICATIONS

  The Army Position and Border Line

  The National Redoubt

  LOCATION

  1. The Army Position and Border Line

  This position stretched from Vallorbe on the French border, to the west of Neuchatel to Basel, then eastward, to Konstanz and the Bodensee. At a short distance behind the Border Defenses,which ran close to the frontier, was the Army Position. At Koblenz the Army Position followed Lake Zurich, joining with the Border Defenses at Fortress Sargans. This last segment formed part of the National Redoubt. An additional section, considered part of the Army Position, covered the region of Bellinzona in the southeast.

  The Swiss built only two forts between Vallorbe and Basel because the rugged Jura Mountains presented a serious obstacle. The forts at Vallorbe and Porrentruy commanded major road junctions where access through the mountain barrier was less difficult. The Rhine formed another natural barrier between Basel and the Bodensee. Here the roads passed through many easily defended defiles, even though the hills south of the Rhine did not reach great elevations. The other end of the Bodensee was covered by Fort St. Margrethen. The northern frontier with Germany was the most vulnerable to invasion.

  2. National Redoubt

  The National Redoubt had three key anchor points: Fortress St.Maurice, Fortress St. Gotthard, and Fortress Sargans that formed the southern and eastern bulwarks of the region. Between St. Maurice and St. Gotthard was the Rhone Valley that included the highest sections of the Swiss Alps, with elevations of over 3,000 meters above sea level. This fortress region followed most of the border with Italy up to the St. Gotthard area and the Rhine Valley northward to Sargans. At this point it abandoned the mountainous eastern quarter of the country.

  The remainder of the redoubt area extended northward from St. Maurice, around the Alps to Thun, and along the line of lakes to Lake Zurich, where it turned eastward, to Sargans. Only two major roads cut through the massive Alpine barrier between St. Maurice and Sargans. Fortress St. Gotthard stood at one end, dominating both of these passages.

  HISTORY

  As in other countries, national defense in Switzerland became part of the economic recovery program from the depression. In 1934, the Swiss Parliament authorized the construction of defenses to employ the jobless. Since the government had recently drained the Linth Plain, opening a new route for the enemy, Fortress Sargans had to be set up to protect it. The new fortress underwent four construction phases between 1938 and 1942, resulting in the most heavily defended area in Switzerland. The other two fortress zones of the National Redoubt were also improved, receiving additional forts.

  Site surveys for the new forts in the National Redoubt and the Border Line were carried out in the latter half of 1935 and construction began in 1937. The new forts neared completion by the summer of 1939. New heavy bunkers were also created to defend both positions. The new Border Line Position, where five forts were erected, was completed between 1939-1940.

  Furthermore, in 1937 the Swiss government committed funds and men to positions on the French and Italian borders to avoid giving the impression that only Germany was being singled out as a potential threat. Most road bridges near the borders were prepared for demolition, obstacles were readied, and key bridges were outfitted with capped holes. In time of war troops would be able to quickly replace the caps with steel anti-tank rails.

  Soon after the war began, the Swiss army leaders concluded that the Border Line was too weak, so work resumed on the Army position. Between October 1939 and the summer of 1940, construction continued on this position, and the Border Line increasingly took on the role of an advance position.

  Late in the 1930s, the government reorganized the army into nine divisions and three independent brigades that formed three corps initially. During the war these three corps were reorganized into four, each retaining a mountain brigade. The III Corps defended Fortress St. Gotthard and most of the National Redoubt.

  The frontier guard consisted of only 1,800 men and the army required two days to mobilize. According to military writer B. H. Liddel Hart, it would have been a simple matter for the enemy to launch a surprise attack on Switzerland and overwhelm its border defenses, especially between November and February when fewer men were on active duty.

  DESCRIPTION

  1. The Army Position and Border Line

  The most common type of structure in the Army Position and the Border Line was the heavy, two-level bunker. Its lowe
r level included crew quarters, munitions storage, and a filter system for protection against gas. The firing rooms, which were on the upper level, mounted machine guns or machine guns and an anti-tank gun. Their concrete thickness was of approximately 2.0 meters with rock work used for reinforcement.

  The Border Line consisted of a line of machine gun bunkers stretching from Basel to Schaffhausen. The bunkers were laid out to create interlocking fields of fire and were spaced 500 to 760 meters apart. The intervals between the bunkers were filled out by blockhouses-also found in the Army Position-that were not self-suffi cient. In addition to these fortified positions, the Border Line included a variety of obstacles. Bridges were prepared for demolitions and outfitted with obstructions, and barbed wire obstacles were deployed along the length of the Rhine.